text: """Bash-like interface extensions for xonsh."""
  import shlex
  import sys
  import re
  
  
  __all__ = ()
  
  
  @events.on_transform_command
  def bash_preproc(cmd, **kw):
      bang_previous = {
          "!": lambda x: x,
          "$": lambda x: shlex.split(x)[-1],
          "^": lambda x: shlex.split(x)[0],
          "*": lambda x: " ".join(shlex.split(x)[1:]),
      }
  
      def replace_bang(m):
          arg = m.group(1)
          inputs = __xonsh__.history.inps
  
          # Dissect the previous command.
          if arg in bang_previous:
              try:
                  return bang_previous[arg](inputs[-1])
              except IndexError:
                  print("xonsh: no history for '!{}'".format(arg))
                  return ""
  
          # Look back in history for a matching command.
          else:
              try:
                  return next((x for x in reversed(inputs) if x.startswith(arg)))
              except StopIteration:
                  print("xonsh: no previous commands match '!{}'".format(arg))
                  return ""
  
      return re.sub(r"!([!$^*]|[\w]+)", replace_bang, cmd)
  
  
  def alias(args, stdin=None):
      ret = 0
  
      if args:
          for arg in args:
              if "=" in arg:
                  # shlex.split to remove quotes, e.g. "foo='echo hey'" into
                  # "foo=echo hey"
                  name, cmd = shlex.split(arg)[0].split("=", 1)
                  aliases[name] = shlex.split(cmd)
              elif arg in aliases:
                  print("{}={}".format(arg, aliases[arg]))
              else:
                  print("alias: {}: not found".format(arg), file=sys.stderr)
                  ret = 1
      else:
          for alias, cmd in aliases.items():
              print("{}={}".format(alias, cmd))
  
      return ret
  
  
  aliases["alias"] = alias
  